Flow restricting valve safety device for fluid filter



NOV. 15, 1966 D, A HARPER 3,285,269

FLOW RESTRICTING VALVE SAFETY DEVICE FOR FLUID FILTER Filed Oct. '7, 1965 ro 24 FL 0/0 REsEm/a/R 7 United States Patent 3,285,269 FLOW RESTRICTING VALVE SAFETY DEVICE FUR FLUID FILTER David A. Harper, Bridgeview, Ill., assigner to International Harvester Company, Chicago, Ill., a corporation of New Jersey Filed Oct. 7, 1963, Ser. No. 314,166 7 Claims. (Cl. 137-118) This invention relates to hydraulic valve devices, but more particularly to a flow-restricting valve type of safety device connected in a circuit with a fluid lter mechanism and operative upon clogging of said lter.

The present invention has for its primary object the provision of a novel safety valve arrangement that will permit directing substantially all of the fiow from a single source of fiuid to one instead of a plurality of hydraulic devices in event of failure or clogging o-f a iiuid filter in the associated hydraulic circuit.

Another object is to provide an improved flow-restricting valve type of safety device adaptable for use with an upstream fluid filter device and adaptable for operation when said filter device becomes clogged.

A further object is to provide an hydraulic circuit wherein a safety flow-restricting valve, positioned downstream from the fluid filter thereof, is operative to interrupt the fiow of a substantial portion of the fiuid flow from said filter and through said valve in event of objectionable clogging of the filter.

A more specific object is to provide in a hydraulic circuit providing flow downstream from a fluid filter and from a single source of fluid to a hydraulic lift pump and to a vehicle transmission charging pump, a flow-restricting valve type of safety device wherein in event of filter clogging a substantial portion of the flow to the lift pump is interrupted from flow thereto and instead is permitted to flow to the said transmission charging pump.

Another more specific object is to provide, in a hydraulic circuit wherein a lift pump requiring a small quantity of lubricating fluid flow when not pumping and a Vehicle transmission charging pump are supplied fluid from a single source in said circuit and are connected downstream of a fiuid filter device therein, an improved flow-restricting valve that will permit a small trickle of fluid fiow to said lift pump after said valve has operated to cut off a substantial portion of the fluid flow therethrough to said pump because of a clogged condition in said filter.

A still further object is to provide a novel warning arrangement for calling an 'operators attention to a clogged fluid filter condition in an associated hydraulic circuit.

The foregoing and other objects and features of the invention will become apparent as the disclosure is more fully made in the following detailed description of a preferred embodiment of the invention as illustrated in the accompanying sheet of drawings in which;

FIGURE l is a generally diagrammatic view, with portions thereof in section, of a hydraulic circuit arrangement showing an application of the present invention;

FIGURE 2 is a vertical sectional view taken generally along the line 2-2 of FIGURE 1; and

FIGURE 3 is a vertical sectional view taken generally along the line 3-3 of FIGURE 1.

Referring now t'o the drawings, it will be noted the proposed invention has been shown as used with a plurality of hydraulic devices in the form of hydraulic pumps although it will be appreciated it is not so limited and may be otherwise employed with other hydraulic devices with equal facility and novelty without deviating from any teachings hereof. A fluid inlet conduit connects at 4one end to a suitable source of fluid (not shown), while Patented Nov. 15, 1966 ICC the other end thereof opens into a fluid filter designated in its entirety by the reference numeral 11. A conduit 12 connects an outlet side of said filter to a hydraulic pump designated 13, while a conduit 14 connects an outlet side of the filter to a cutoff valve device represented generally by the reference numeral 15, and an outlet of said valve assembly connects by conduit 16 to a hydraulic pump designated by the reference character 17.

The filter unit 11 which may be generally conventional in construction will be seen to include a hollow cylindrical casing 18 which has a cap-like cover 19 threaded onto one end, a sealing gasket 20 being inserted between said cap cover and the casing to prevent leakage, and the inner walls of the casing may be said to define a filter charnber such as 21. A filter element, such for instance as the cylinder of fine mesh screening indicated at 22, is mounted at one of its ends on the cap 19 and extends into the chamber 21 coaxially therewith, while the other end of the filter element may be closed by suitable means such as the plate 23. It will be appreciated that many other filtering elements of well-known forms may be employed with equal facility herein without deviating from any of the inventive concepts disclosed herein. An intake port 24 is provided in cap 19 to communicate with the interior of the filter element and a plurality of outlet ports 25 and 26 are provided in the cylindrical wall of casing 18 to communicate with the interior chamber 21. The interior of the filter element thus constitutes the intake side of the filter while the remainer of the chamber 21 constitutes the outlet side of the filter and outlet conduits 12 and 14 are connected with the respective outlet ports 25 and 26 of the filter unit 11.

Hydraulic pump 13 may be any conventional or wellknown vehicle transmission charging pump, while pump 17 may be any conventional hydraulic li-ft pump both of which pumps will, of course, as is understood, be suitably driven by power means on the associated vehicle, none of which are shown since the details thereof are not particularly pertinent to the actual inventive concepts hereof.

The proposed cutoff or flow-restricting valve 15 comprises a casing 27 having a circular bore 28 therethrough and one end of said bore provides a port opening 29 for connection with outlet conduit 16, While the opposite end of said bore has an apertured cover plate 30 thereover which is suitably detachably secured to said casing by fastening bolts 31. An aperture 32 in said cover plate opens into the proximate end of said bore for purposes to be subsequently explained. An enlarged opening or recess 33 extending inwardly from one wall of casing 27 opens into bore 28 and the outer end thereof provides an inlet port 34 for connection thereto of inlet conduit 14 from the filter 11. An enlarged counterbore portion 35 of bore 28 has a sleeve-like member 36 fitted thereinto in a fluid-tight-fit relationship and is provided with a plurality of axially extending apertures 37 circumferentially spaced in the wall of said sleeve. Said latter apertures are so disposed as to open outwardly into the enlarged recess or opening 33 while the interior thereof opens into and communicates with said bore. The sleeve member 36 is adapted to slidably receive a hollow piston member 39 and a thickened portion 40 at one end of said sleeve provides a shoulder 41 that functions as an abutment or stop to limit inward axial movement of piston 39. Said piston has fashioned therein a plurality of small diametered openings 38 circumferentially spaced from one another and axially spaced from the larger apertures 37 of said sleeve member.

A coil spring 42 is dimensioned to fit into a hollow piston 39 and to abuttingly seat against the inner end surface thereof while the opposite end of said spring abuts a snap-ring 43 disposed in an annular recess 44 in the thickened portion 40 of sleeve member 36. Normally the spring 42 biases the piston 39 into position such that the end f said piston abuts cover plate 30 thus permitting full fluid flow through the valve by way of apertures 37.

In operation, hydraulic fluid would normally be flowing from the source thereof by way of conduit into filter 11 thence through said filter and out by way of conduits 12 and 14. Conduit 12 connects with pump 13 which, as previously indicated, may be used to provide a transmission charging fluid under pressure, while conduit 14 connects into inlet port 34 of the valve device 15. Fluid entering port 34 of said valve device, passes through apertures 37 in sleeve member 36 and, since piston 39 is normally axially displaced, to the right as viewed herein, by the reaction of spring 42, leaving the apertures 37 free and unobstructed for the passage of fluid therethrough, the fluid flows freely by way of bore 28 and conduit 16 ultimately into lift pump 17, thus both pump 13 and pump 17 are supplied from the same fluid source.

Now, whenl the filter element 22 becomes objectionably clogged and thus tends to limit the free passage of fluid therethrough, the suction in valve reaches a predetermined vacuum, `as established by spring 42 and the exterior area on piston 39 exposed to atmospheric pressure and whereupon the atmospheric pressure acting through aperture 32 against piston 39 on the exposed area thereof overcomes the resistive force of spring 42 and moves the piston 39 inwardly. As the piston moves oil flow is being metered across the apertures 37 and the end surface of said piston and such metering tends to increase the vacuum within said port thus aiding the atmospheric pressure on the piston area to fully overcome spring 42 and move piston 39 until it abuttingly seats against shoulder 41 and thus closes off the apertures 37. In this closed position of piston 39 substantially all of the oil flow will be diverted by way of filter 11 to pump 13 which, in this case, would be the pump with the highest flow demand priority. This demand priority is true in the instant case because pump 13 provides for transmission operation which is essential for mobility of the associated vehicle. At the same time pump 17 is supplied Iwith a small trickle of fluid flow by way of the openings 38 which flow is sufficient to provide necessary lubrication demands of said latter pump and thus prevent damage thereto. When this occurs the operator would soon learn that the lift pump 17 was not capable of functioning to lift and hence would immediately be put on notice that the oil filter was clogged beyond normal tolerance and required examination and possible cleaning. In this manner, the device functions as a warning means for putting the operator on notice of possible clogging in the oil filter while concomitantly therewith diverting substantially al1 the fluid flow to the highest priority demand device.

It should now be apparent that a novel cutoff valve type of safety device has been shown and described, and it is to be understood that changes may be made in the construction without departing from the spirit of the invention or the scope thereof as defined in the appended claims.

What is claimed is:

1. In a hydraulic circuit having a fluid filter device adapted for connection to a reservoir source of fluid and a plurality of hydraulic devices, the combination, comprising: a control assembly for regulating the flow of fluid to said devices; first and second conduit means connecting said assembly respectively with said filter device and with one of said hydraulic devices; third conduit means connecting said filter device with another one of said hydraulic devices; said control assembly including fluid flow interrupting means operative upon an increase in vacuum in said first and second conduits to restrict the flow of fluid therethrough to said one of said hydraulic devices.

2. In a hydraulic circuit having a fluid filter device adapted for connection to a reservoir source of fluid, and first and second hydraulic fluid devices connected downstream of said filter, the combination, comprising: a control assembly for regulating the flow to said devices; first and second conduit means connecting said control assembly respectively with said filter device and with said second hydraulic fluid device; third conduit means connecting said filter device with said first hydraulic fluid device; said control assembly having valving means therein normally disposed to permit full fluid flow` therethrough from said filter to said second hydraulic fluid device and operative responsive to an increase in vacuum in said first conduit to limit the flow of fluid therethrough to said second hydraulic fluid device.

3. In a hydraulic circuit having a fluid filter device adapted for connection to a reservoir source of fluid, and a first high priority fluid demand hydraulic pump yand a second low priority fluid demand hydraulic pump communicatively connected to a downstream side of said filter device, the combination, comprising: a control assembly for regulating fluid flow t-o said devices; first and second fluid-carrying conduit means connecting said control assembly respectively with said filter device and with said second hydraulic pump, and third fluid-carrying conduit means connecting said filter device with said first hydraulic pump; said control assembly being fashioned to provide valving means therein normally disposed to permit full fluid flow to -said second hydraulic pump while full fluid flow is being concomitantly provided to said first hydraulic pump, and having said valving means operative responsive to an increase in vacuum in said first conduit resulting from a clogged filter to limit flow of fluid therethrough to a small trickle thereby t0 permit said first hydraulic pump to receive a substantial portion of the fluid flow passable through said filter.

4. In a vehicle hydraulic circuit having a fluid filter device with upstream and downstream sides and adapted for connection on the upstream side thereof to a reservoir source of fluid, a hydraulic transmission charging pump and a hydraulic lift pump, the combination, comprising: a control assembly for regulating fluid flow to said lift pump; first and second fluid-carrying conduit means connecting said assembly respectively with the downstream side of said filter device and with said hydraulic lift pump, and third fluid-carrying conduit means connecting the downstream side of said filter device with said hydraulic transmission charging pump; said control assembly being fashioned to provide valving means therein normally disposed when open to permit full fluid flow therethrough to said hydraulic lift pump and limited fluid flow therethrough to said lift pump when closed; such valving means being operative responsive to an increase in vacuum in said first conduit resulting from a clogged filter to close said valving means and restrict fluid flow thereto to said limited fluid flow thereby permitting substantially increased fluid flow to said transmission charging pump.

5. In a vehicle hydraulic circuit having a fluid filter device with upstream and downstream sides and adapted for connection on the upstream side thereof to a reservoir source of fluid, a hydraulic transmission charging pump and a hydraulic lift pump, the combination, comprising: a control assembly for regulating fluid flow to said lift pump; first and second fluid-carrying conduit means connecting said assembly respectively with the downstream side of said filter Idevice and with said hydraulic lift pump, and third Yfluid-carrying conduit means connecting the downstream side of said filter devieewith said hydraulic transmission charging pump; said control assembly iucluding a casing having an inlet connected to said first conduit means, and an outlet connected to said second conduit means, and means forming a full fluid flow passage therethrough; valving means in said full flow fluid passage normally disposed to permit full fluid flow therethrough from said inlet to said outlet; said valving means including means therein forming limited flow fiuid passages therethrough; said valving means being operative responsive to an increase in vacuum in said inlet resulting from a clogged filter to interrupt the full fiow of liuid therethrough and to permit iiuid flow through'said limited flow passages whereby said lift pump is provided with a limited iioW of uid while concomitant therewith a substantial portion of the flow through said iilter device is directed to said transmission charging pump.

6. A flow-restricting valve assembly for controlling the flow of liuid to a hydraulic device, comprising: a casing having a bore fashioned therethrough and having a first port opening therein communicating with said bore and adapted for connection to a reservoir source of fluid, and a second port opening formed at one end of and communieating with said bore and adapted for connection to a hydraulic device; a tubular sleeve member disposed in said bore and having a plurality of apertures therein arranged to permit full fluid communication therethrough between said port openings; a piston member slidable in said sleeve and disposed for slidable movement therewithin to close said apertures; means providing a closure abutment at one end of said bore to prevent movement of said piston outwardly beyond said casing; said piston including means forming small diametered uid passages through said piston; means forming an abutment on the interior of sai-d sleeve; resilient means reactively disposed between said abutment means and said piston for normally maintaining said piston in position such that said apertures are unrestricted to the ow of uid therethrough while said small diametered passages are closed to the passage of fiuid; said piston being operative responsive to an increase in vacuum in said first port opening for slidable movement within said sleeve for interrupting the flow of uid through said apertures and concomitant therewith opening sai-d small diametered fluid passages to permit limited fluid flow therethrough to said second port openmg.

7. A How-restricting device for controlling the flow of fluid to a hydraulic lift pump, comprising: a casing having a bore fashioned therethrough, and having a first port opening therein communicating with said bore and adapted for connection a reservoir source of uid, and

a second port opening formed at one end of and in communication with said bore and adapted for connection to a hydraulic Ilift pump; a tubular sleeve member disposed in said bore and fashioned with a plurality of circumferentially spaced Iand axially extending apertures therein arranged to accommodate full iiow of fluid therethrough between said port openings; a hollow piston having one open and one closed end thereof and being disposed for slidable movement within said sleeve to close said sleeve apertures, and having an outwardly facing surf-ace on said closed end exposed to atmospheric pressure and normally aligned with an outer end edge of said bore; means providing a closure abutment on said casing at one end of said bore t-o prevent movement of said sleeve and said piston outwardly beyond the end of said bore; said piston having a plurality of circumferentially spaced, radially extending small-diametered openings axially spaced intermediate the ends thereof; means forming an abutment on the interior of said sleeve proximate said apertures therein; spring means disposed with one end thereof seated against said sleeve abutment and having another end at said spring extending into said hollow piston and abutting an interior surface of said closed end portion and being reactive for normally maintaining said piston in position such that said sleeve apertures remain -unobstructed and open to full iiuid ow therethrough while the small-diametered openings of said piston are closed to the passage of fluid; said piston being operable responsive to an increase in vacuum in said first port opening for slidable Iaxial movement within said sleeve for interrupting the flow 'of uid through said sleeve apertures and concomitant therewith opening said small-diametered uid openings to the passage of a limited ow of fluid therethrough to said second port opening.

References Cited by the Examiner UNITED STATES PATENTS 5/1935 Hempstead 137--483 X 10/1951 Noon 137-118 

7. A FLOW-RESTRICTING DEVICE FOR CONTROLLING THE FLOW OF FLUID TO A HYDRAULIC LIFT PUMP, COMPRISING: A CASING HAVING A BORE FASHIONED THERETHROUGH, AND HAVING A FIRST PORT OPENING THEREIN COMMUNICATING WITH SAID BORE AND ADAPTED FOR CONNECTION A RESERVOIR SOURCE OF FLUID, AND A SECOND PORT OPENING FORMED AT ONE END OF AN IN COMMUNICATION WITH SAID BORE AND ADAPTED FOR CONNECTION TO A HYDRAULIC LIFT PUMP; A TUBULAR SLEEVE MEMBER DISPOSED IN SAID BORE AND FASHIONED WITH A PLURALITY OF CIRCUMFERENTIALLY SPACED AND AXIALLY EXTENDING APERTURES THEREIN ARRANGED TO ACCOMMODATE FULL FLOW OF FLUID THERETHROUGH BETWEEN SAID PORTS OPENINGS; A HOLLOW PISTON HAVING ONE OPEN AND ONE CLOSED END THEREOF AND BEING DISPOSED FOR SLIDABLE MOVEMENT WITHIN SAID SLEEVE TO CLOSE SAID SLEEVE APERTURES, AND HAVING AN OUTWARDLY FACING SURFACE ON SAID CLOSED AND EXPOSED TO ATMOSPHERIC PRESSURE AND NORMALLY ALIGNED WITH AN OUTER END EDGE OF SAID BORE; MEANS PROVIDING A CLOSURE ABUTMENT ON SAID CASING AT ONE END OF SAID BORE TO PREVENT MOVEMENT OF SAID SLEEVE AND SAID PISTON OUTWARDLY BEYOND THE END OF SAID BORE; SAID PISTON HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED, RADIALLY EXTENDING SMALL-DIAMETERED OPENINGS AXIALLY SPACED INTERMEDIATE THE ENDS THEREOF; MEANS FORMING AN ABUTMENT ON THE INTERIOR OF SAID SLEEVE PROXIMATE SAID APERTURES THEREIN; SPRING MEANS DISPOSED WITH ONE END THEREOF SEATED AGAINST SAID SLEEVE ABUTMENT AND HAVING ANOTHER END AT SAID SPRING EXTENDING INTO SAID HOLLOW PISTON AND ABUTTING AN INTERIOR SURFACE OF SAID CLOSED END PORTION AND BEING REACTIVE FOR NORMALLY MAINTAINING SAID PISTON IN POSITION SUCH THAT SAID SLEEVE APERTURES REMAIN UNOBSTRUCTED AND OPEN TO FULL FLUID FLOW THERETHROUGH WHILE THE SMALL-DIAMETERED OPENINGS OF SAID PISTON ARE CLOSED TO THE PASSAGE OF FLUID; SAID PISTON BEING OPERABLE RESPONSIVE TO AN INCREASE IN VACUUM IN SAID FIRST PORT OPENING FOR SLIDABLE AXIAL MOVEMENT WITHIN SAID SLEEVE FOR INTERRUPTING THE FLOW OF FLUID THROUGH SAID SLEEVE APERTURES AND CONCOMITANT THEREWITH OPENING SAID SMALL-DIAMETERED FLUID OPENINGS TO THE PASSAGE OF A LIMITED FLOW OF FLUID THERETHROUGH TO SAID SECOND PORT OPENING. 